The more stylised someone's work is, the more difficult it is to critique it properly. At least, without having people scream ITS MAH STYLE BITCH. Since your sprites are much more, well, Sonic-like, its easier to compare them to official Sonic art and say what's right and what's wrong. Just like when someone's trying to draw a realistic-looking human, its easier to say what needs fixing with it than a drawing of the Powerpuff Girls.
The only thing I have to compare Ironhind's work to is Sonic Epoch. And let's be fair - that wasn't a treat for the eyes in the first place.
Btw decent Sonic.